If you have upgraded your version of Asterisk and find that your IAX2 extensions no longer work then the cause could be a change to the IAX protocol. This was made to resolve a security issue that could result in a denial of service attack. You will see this error in the Asterisk log file if you are suffering from this issue – chan_iax2.c: Call rejected, CallToken Support required. If you use FreePBX then Asterisk can be made to function the same as before by adding the following 2 lines to /etc/asterisk/iax_general_custom.conf – calltokenoptional = 0.0.0.0/0.0.0.0 maxcallnumbers = 16382 You…